This chapter considers the connection between subjectivity and the frequently under-analysed affective qualities of advanced composition within a later modernist tradition. It begins by untangling the ways in which the diversity of affective experience may be approached theoretically and assesses contributions to modernist music studies within the context of the ‘affective turn’ in the humanities. The distinctions between affect, emotion and feeling are examined and considered in terms of their applicability to musical analysis and discourse. Two brief case studies are provided which examine these different states in the writings and music of Tristan Murail and Iannis Xenakis. The chapter concludes by returning to the questions of subjectivity and proposes that one way of conceiving the focus on emotion and affect is as a way of productively sidestepping the otherwise unresolved questions of the subject’s ontological and epistemological status in late modernity.